1. Field of the Invention
The invention relates to crosslinkable compositions with very high storage stability, based on organosilicon compounds to a process for their preparation, and also to their use.
2. Background Art
Single-component sealing compositions (RTV-1) which are storable if water is excluded but which vulcanize to give elastomers at room temperature when exposed to water have been known for a long time. Large amounts of these products are used for example in the construction industry. These mixtures are based on polymers terminated by silyl groups bearing reactive substituents such as OH groups, or hydrolyzable groups, e.g. alkoxy groups. These sealing compositions may also comprise fillers, plasticizers, crosslinking agents, catalysts, and other additives. Among the known fillers are fine-particle metal oxides and metal salts. When these are used in sealing compositions they can not only optimize selected performance characteristics of the cured product but also improve the specific properties of the sealing composition during application.
EP 10104787 B describes, for example, the use of materials known as heavy calcium carbonates, obtained via milling of limestone. Furthermore, DE 195 07 416 C discloses the use of precipitated chalks in RTV-1 silicone rubber compositions. The use of ground natural chalks is also mentioned. However, a particularly problematic factor described here was the poor storage stability of RTV-1 silicone rubber compositions which eliminate alcohol, this being discernible as markedly delayed hardening following application. Additions of orthophosphoric esters for improving storage stability are disclosed.
DE 101 21 514 A also describes an improvement in the storage stability of RTV-1 silicone rubber compositions which eliminate alcohol, using tin catalysts which have phosphorus compounds as ligands. Emphasis is placed on the possibility of preparing colorless, transparent RTV-1 silicone rubber compositions.